Dementia: Four Types and Their Symptoms
December 20, 2021
In articles about aging, you may have read the phrase, “Alzheimer’s and other dementias…” There are several different types of dementia, with Alzheimer’s being the most common. The National Institute on Aging explains that dementia is an umbrella term used to describe a range of neurological conditions affecting the brain that get worse over time. It provides the following information about these conditions.
As we age, it’s normal to lose some neurons in the brain. People living with dementia, however, experience far greater loss. Many neurons stop working, lose connections with other brain cells, and eventually die. At first, symptoms can be mild, but they get worse over time. There are different types of dementia, including “mixed dementia,” a combination of two or more types of the disease. Here is some basic information about the four most common types.
- Alzheimer’s disease
Alzheimer’s disease is caused by abnormal deposits of proteins that form amyloid plaques and tau tangles throughout the brain. Symptoms can change over time:
- Mild: Wandering and getting lost; repeating questions.
- Moderate: Problems recognizing friends and family; impulsive behavior.
- Severe: Inability to communicate.
The typical age of diagnosis for Alzheimer’s disease is the mid-60s and above, with some cases diagnosed starting in the mid-30s.
- Frontotemporal dementia
This condition is caused by abnormal amounts or forms of tau and TDP-43 proteins that accumulate inside neurons in the frontal and temporal lobes. The symptoms include:
- Frontal lobe: The patient shows behavioral symptoms such as difficulty resisting the impulse to use or touch objects, or compulsive eating.
- Temporal lobe: The patient experiences language and emotional disorders. They may be unable to understand the meaning of words or speak properly, for example. Or they may have difficulty understanding facial expressions and personal relationships.
The typical age of diagnosis of frontotemporal dementia is between 45 and 64.
- Lewy body dementia
Abnormal deposits of the alpha-synuclein protein, called “Lewy bodies,” affect the brain’s chemical messengers. Symptoms include:
- Cognitive decline: The inability to concentrate, pay attention, or stay alert; being disorganized or having illogical ideas.
- Movement problems, such as muscle rigidity, loss of coordination, or reduced facial expression.
- Sleep disorders, including insomnia and excessive daytime sleepiness.
- Visual hallucinations.
The typical age of diagnosis of Lewy body dementia is 50 and older.
- Vascular dementia
With vascular dementia, various conditions, such as blood clots, disrupt blood flow in the brain. Symptoms may include:
- Forgetting current or past events.
- Misplacing items.
- Trouble following instructions or learning new information.
- Hallucination or delusions.
- Poor judgment.
The typical age of diagnosis of vascular dementia is 65 and older.
Diagnosis for these four types of dementia
Symptoms can be similar among different types of dementia, and some people have more than one form of dementia, which can make an accurate diagnosis difficult. Symptoms can also vary from person to person. Doctors may ask for a medical history, complete a physical exam, and order neurological and laboratory tests to help diagnose dementia.
The information in this article is not intended to replace the advice of your healthcare provider. Talk to your doctor with questions about your health.